1. Field of the Invention
This invention relates to conductive polyether based fluoro-resin compositions which cure into parts having high conductivity, improved heat resistance, weather resistance and solvent resistance and optionally forming firm bonds to various substrates. The compositions are effective in die bonding of semiconductor devices and mounting of quartz crystal oscillators.
2. Prior Art
Conductive compositions loaded with silver particles find major applications in die bonding of semiconductor devices and mounting of quartz crystal oscillators. The prior art conductive compositions used in this field are epoxy resin compositions loaded with silver particles.
With the recent advance in precision of devices and parts, however, conductive epoxy resin-based compositions tend to impose substantial stresses to parts and devices on account of the rigidity of the epoxy resins and thus have a considerable influence on the assembly properties. Softer rubbery conductive materials are thus desirable. Conductive adhesives of the silicone class are proposed, for example, in JP-A 133432/1995 corresponding to EP 653,463.
The conductive siloxane composition of this patent experiences a substantial change of conductivity by heat shocks. The influence of low molecular weight compounds on the surrounding electric parts is of concern, which is another drawback of the siloxane composition. There is a desire to have conductive materials of higher quality.